In the field of dispensing liquid material, such as soap, from a container, different dispenser system types are known. Liquid dispensers, particularly soap dispensers, of the type which contain a replaceable liquid container are becoming more and more popular. Using a replaceable liquid container allows users and suppliers to rapidly refill an empty dispenser, or to change the type of liquid without having to clean or change the dispenser itself.
The system may either include a container which is rigid or collapsible. While a rigid container maintains its shape upon being emptied, a collapsible container is gradually collapsing, i.e. its inner volume is decreasing as fluid is dispensed therefrom. Collapsible containers are particularly advantageous in view of hygienic considerations, as the integrity of the container is maintained throughout the emptying process, which ensures that no contaminants are introduced thereto, and that any tampering with the content of the container is impossible without visibly damaging the container.
One type of collapsible containers is simple bags, generally formed from some soft plastic material. Bags are generally relatively easy to collapse, and the bag walls would not strive to re-expand after collapse. Hence, the bag walls would not contribute to any negative pressure in the bag.
Another type of collapsible containers is known from e.g. EP 0 072 783 A1 and DE 90 12 878 U1. This type of collapsible containers has at least one relatively rigid wall, towards which the collapse of the other, less rigid walls of the container will be directed. Hence, hereinafter, this type of container is referred to as a semi-rigid collapsible container. A second example of a semi-rigid collapsible container is found in U.S. Pat. No. 5,083,678. This container is made of thermoplastic material and is collapsible from a first configuration to a second configuration during the dispensing of the liquid material.
Irrespective of whether a rigid or collapsible container is used, one of the concerns that is to be considered when designing dispensing systems for liquid materials arises when the container is about to be depleted, requiring it to be replaced by a new, full container. Unlike other dispensers, such as paper dispensers which dispense stacks of folded tissue paper and which can be easily refilled simply by placing additional paper on top of the almost depleted paper stack, such an easy refill is difficult to obtain for a liquid dispenser system.
Known dispensing systems for liquid materials normally have supply bottles, or containers, which are placed upside down in a dispenser to maintain a positive flow of liquid from the outlet or pump, if the outlet is connected to a pump. Several versions of controlling the flow of liquid from the container have been in use during the years. A pump that could be dislodged from the old container and fitted to the new one, has later been replaced with a pump integral in the container, to ease the maintenance work and make sure that no old deposits will clog up an old pump. Often the lever or dosing member to work the pump has been part of the main dispenser body, but other times it has been part of the container itself. It has been found that during usage of such dispensing systems, the replacement of the container should be carried out at the right timing to prevent the container from being fully emptied.
In order to accomplish this, U.S. Pat. No. 4,570,823 suggests a soap solution dispenser having a float body in the reservoir, i.e. container. The float body is provided with at least one indicator flag coupled thereto and the path of movement of the indicator flag extends along a viewing window of the cover. In this manner, the consumer or the user of the dispenser is provided with an indication of the filling state of the soap solution dispenser at a small expense.
US 2008/023487 A1 is another document relating to a dispenser including a collapsible reservoir. The dispenser also contains a tensioning element for stretching the reservoir so as to counteract, or negate, the compression of the reservoir. By applying this stretching, the bulging of the reservoir is pulled inward in a homogenous manner. In this way, the risk of fluid getting trapped in the reservoir is minimised since the risk of having excessive crumpling is decreased. The dispenser further includes an inspection window, which allows the amount of liquid in the reservoir to be seen from outside.
As regards other known arrangements, WO 2009/113920 A1 discloses a bag-in-box type liquid receptacle having an indicating sheet which is attached to the upper wall of the outer container. The indicating sheet is further provided with a flap, running in an opening of the outer container, for visually displaying the liquid level of the inner container. Hence, it is not required to open the outer container and take out the inner container therefrom to determine the amount of liquid which is left in the inner container. However, this type of receptacles is intended for being located on a horizontal surface such as a dining table or kitchen worktop, and is not suitable for use in systems with a reused outer container and exchangeable inserts and is therefore not suitable for being mounted on a wall in restrooms.
Despite the activity in the field, exemplified by the above-cited disclosures, there remains a need for a dispensing system including a collapsible container, which combines high functionality and simplicity with the possibility of identifying when the system is running out of liquid material.
Advantageously, the dispensing system should be suitable for liquid materials such as soap.